Pencil sharpener



2 Shn-ts-Slnee-tV 1 PQFRENELL PENCIL SHARPENER Filed Feb. 2v, 1923 O a .l- W .5.. r| e 1 Z /WH Feb. 3. 1925.

Patented Feb. 3, 1925.

UNITED STATES PER FRENELL, F GOTTENBORG, SWEDEN.

PENCIL SHARPENER.

Application led February 27, 1923.

To f/ZZ whom t may concern:

Be it known that I, PER F RENELL, civil engineer, subject of the King of Sweden, residing at Kopniansgatan 52, Gottenborg, in the Kingdom of Sweden, have invented certain new and useful Improvements in Pencil Sharpeners; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Thel present invention has for its object improvements in apparatus for the sharpenine' of lead pencils or the like (so-called pencil Sharpeners) of the type where the cutter or cutters are connected in such a manner with a shaft rotatably arranged in a. supporting frame, that during the revolution of the shaft the part of the pencil which is to be sharpened, while it is being fed through a holder for the pencil in the path of the rotating edges, will be out or sharpened along corresponding cuts or sections arched in relation to the longitudinal axis of the pencil.

According to the present invention the cutters consist of knife blade-s, for example of double edged safety razor blades, or the like blades, which are detachably fitted in arms or the like projecting from the rotating shaft the outer surface of which arms are so bent or shaped that the blades resting against said surface in working position are arched in cross-section, whereas the cutting edges of said blades are so formed or arranged that they extend subtantially lengthwise of the shaft whereby the advantage of au etlicient construction is gained.

In order to facilitate the cutting during the sharpening process and at the same time to utilize the cutter blades in the best way the cutter is according to one form of the invention arranged in such a way that during the revolution of the shaft, the shaft itself or the parts carrying the cutter blades are given a slow reciprocating movement lengthwise of the shaft.

It is before known to use razor blades of the kind mentioned for sharpening of lead pencils, for instance in such a way that the edges of the blade have their principal extension lengthwise of the pencil, which, however, is connected with some drawbacks obviated by the present invention, but as far as I know it is not before Serial No. 621,570.

known in apparatuses above described to have the blades arranged in the manner described in the present patent.

In order, however, to facilitate the cutting during the sharpening process, in one form of the present invention the cutters are arranged in such wise that during the revolution of the shaft they are subjected not merely to the rotary motion, but at the same time also to a slow reciprocating motion in relation to the pencil or the supporting frame, in addition to which arrangements are provided for the automatic feeding and rotation of the pencil according as thesharpening proceeds. Blades of safely razors of the so-called Gillette type can, in accordance `:with the prese-nt insI vention. be used with advantage as cutters.

The advantages of the use of razor blades of the type above referred to are that they are excellently adapted for the purpose, and moreoverv that they can easily be procured as they are sold everywhere. Razor blades of the above mentioned type which have been used for their original purpose, i. e. those which have been discarded for the purpose of shaving can very well be used for the sharpening' of pencils, in which case the oost of the knives or cutters will be very small or negligible. These razor b-lades are suitable also for the reason that they can very easily be curved or bent in the manner required for the purpose. in question. Obviously, blades specially manufactured for the purpose can also be employed.

In order to make plain the invention, an example thereof is shown in the accompany ing drawing. Fig. 1 shows the pencil Sharpener viewed from above. Fig. 2 shows a vertical section along the line 2-2 in Fig. 1. Fig. 3 shows a vertical section along the line 3 3 in Fig. 1. Fig. 4 shows in vertical section a detail of a guiding and feeding device for the pencil in a certain working position during the sharpening. Fig. 5 shows a detail, Figs. 6 and 7 show another detail in two different working positions. Figs. 8, 9, and 11 show viewed from above and from the side respectively details of the clamping device illustrated in Figs. 6 and 7.

The pencil Sharpener consists of a supporting frame 13, provided with a covering or casing 17, and with a shaft 16 rotatably journalled in the latter, on which shaft are arranged holders, arms or the like 1, which carry cutters 30, which, if, as shown in the drawing, they consist of such thin blades as are used in safety razors of the Gillette type, may be fixed to the holders 1 by means of a screw 5st provided with a suitable head 2 and a wing nut As is shown iniFig. 3, the head 2 and the corresponding part of the holder 1 are so shaped that the blade 30 will be arched in cross section, and the outer surface of the head2 is so rounded fand shaped that it 'does not project beyond-the cylindrical surface which, on the revolution of the shaft, is determined or passed by thel cutting edges of the knives i. e. the leading edges of the blades when the shaft is rotated in the direction indicated by the arrow in Fig. 3.

During the sharpening process the pencil inserted iii the socket 1K1- united with the supporting f. frame 13i and arranged in a known manner, the socket being adjustably fixed to the frame by screws or other suit-- able iiieans. The socket 111 is provided with another socket 9 iotatably arranged in the latter .and adjustable in its longitudinal direction, in which socketl 9 the pencil is in- Jteiided to be inserted and jammed. For this purpose the socket 9 at its upper part is provided with a clamping device for the secure holding of the pencil, comprising a plate 1() fixed to the socket, On the said pla-te are arranged jaws 11, 12 rotatable round a. pivot 33 and provided with teeth 56, 57 (see Figs. 6-11) whichv jaws are furnished with clamping plates 58, 59, so that by pressing these plates against one another with the lingers the jaws 56, 57 are moved apart from one another (are opened) in the ina-nner indicated in Fig. 7, so that the pencil can be inserted in the sockets 9 and 14whereupon,

after the clamping plates have been released, the jaws by the action of coil springs 34 attached at their one ends by screwvsy to the plate 1() and at their other ends to each of the clamping plates 58, 59, are bro-ught towards one another so as to grip the pencil.

The socket 9 is further provided with a toothed wheel 7 surrounding it and resting against the socket 1/1, and said socket is moreover so arranged in the latter socket that it can be displaced in its longitudinal direction in the central opening of the toothed wheel, but on the rotation of the wheel 7 is broughtto rotate with, the latter. For the latter purpose the socket 9 is provided with two grooves (see Figs. 4,5) ar- 'aiiged in its lengthwise direction, and the toothed wheel 7 is furnished with two teeth 52, or the like, entering into the said grooves. The radius of the toothed wheel 7 is greater than the radius of the top opening of the socket 1e, and it is kept inl place even when the socket 9 is lifted or raised through the action of a flange 63 projecting over the toothed wheel 7 and arranged on the upper part of the socket 14 (see Fig. t). The toothed wheel 7 gears with a worin 8 formed on or mounted on the shaft 15. The shaft 15 is so arranged that it can be rotated simultaneously with the shaft 16 by means of a toothed wheel t provided with a handle 26, which wheel is mounted on a journal 19 fixed in the covering; the said wheel 4l, which is ,provided with inward teeth, is in mesh with toothed wheels 5 and 6 arranged respectively on the shafts 15 and 16. Under the socket 9 a. rest or shoulder 27 for the tip of the pencil is adjustably fixedr is, so that the cutting takes place simul-L taneously both along the pencil, i. e. essentially in the direction in which the. fibres run, and along the edges of the cutter or cutters, the latter are arranged in such wise that, as indicated iabove, they are subjected not merely to the rotary motion but also to a slow reciprocating motion in relation to the pencil which is to be sharpened i. e. in relation to the supporting frame 13. This may be effected either by imparting to the shaft 16 carrying the cutters, by a device suitable for the purpose, a slow longitudinal reciprocating motion in relation'tothesupporting frame, the knives also participating in that motion or else by arranging the knives or knife-holders in such wise as to impart `to them, during the revolution of the shaft, a slow reciprocating axial motion in relation to the shaft. On the appended drawing is shown an example of the lastiiientioned device, in which the shaft is rotatable, but in the axial direction not displa-ceably arranged in the supporting frame.

According to the example shown in the drawing, the shaft 16 for the aforesaid purpose is provided with a sciew-formed groove 53, extending symmetrically round the shaft and forming a closed path; the groove extending along the shaft for a distance corresponding to the required lengthwise movement of the knives (see Fig. 2).V In the nave 62 of the holder 1 foi' the knives a ball, roller, or the like, 29 is journalled, part of it entering into the aforesaid groove. By this arrangement the holder 1, on the rotation of the shaft 16 for the purpose of Athe sharpening, will participate in the rotation of the shaft 1 but, owing to the reiioY Vwise direction of the shaft.

sistance of the pencil to the cutters, the revolution of the holder will be retarded somewhat in relation to the revolution of the shaft, as the ball will run into the groove 53, whereby a slow reciprocating motion, corresponding to the shape and extent, in an axial direction, of the groove 53, will be communicated also to the holder. The greater the resistance of the pencil to the cutters, the greater will be the retardation or drag of the holder in relation to the rotary motion of the shaft, and thereby also the reciprocating motion of the holder in the length- This motion, however', can also be regulated somewhat vby varying` the degree of tension with which the ball is ammed into the groove 53, whereby the friction is increased (or diminished). The regulation of this tightening or jamming can be effected by means of the screw 25 screwed into the nave 62 of the holders 1, which screw rests at its inner end against the ball. The said screw may suitably be provided with a lock-nut 23, so that it can be locked in the desired position. The ball 29 may be inserted or removed for the purpose of renewal, by removing the screw 25. It should be obvious that, instead of using the ball 29, it is also possible to arrange a pin or the like which enters into the groove 53, for the purpose of the required movable locking of the shaft 16 and the knife-holders to one another. It should also be manifested that, instead of arrangingthe groove on the shaft, it is also possible to arrange a corresponding groove in the inner surface, resting against the shaft, of the nave 62, the yielding locking of the holder to the shaft being effected with the aid of a device analogous to that above described.

Analogous devices may also be employed in order to effect the reciprocating motion of the shaft lengthwise in relation to the supportingframe, or the pencil; for example, the ball 29, or a corresponding pin, may be journalled in a fixed position in relation to the supporting frame and enter into a groove in the shaft, corresponding to the groove 53. For the said purpose also other generallyT known devices may obviously be employed, such as cam surfaces, or the like, suitably formed, against which the shaft, for example by the action of springs, is pressed, and is consequently compelled during the rotation to move to and fro in a lengthwise direction.

The pencil sharpener is used and operates in the following manner:

hen a pencil is t be sharpened, the socket 9 is pulled up some distance out of the socket 14, and the jaws 11, 12 are caused to open (see Fig. 7) by pressure against the clamping plates 58, 59, whereupon the pencil is slipped down or inserted into the socket and is gripped by the jaws, on the release of the clamping plates (see F ig. On the turning of the toothed wheel et by means of the handle Q6 the shafts 15 and 1G are set in rotation. The holder 1 arranged on the shaft 16 together with the cutters fixed to it will thereby be brought to rotate, during which rotation the cutters will come into contact with the lower part of the pencil and sharpen it. Owing to the rotation of the shaft the socket 9 and the pencil inserted therein will also be rotated, so that the pencil, according as the sharpening proceeds, will be lowered into the socket 111 until the tip of the pencil finally rests against the adjustable shoulder 27, whereupon the sharpening automatically ceases. During the sharpening as has been indicated above, the cutters will move slowly to and fro in an axial direction in relation to the pencil, so that almost the entire length of the cutting edges will participate in the sharpening, whence the cutters will be utilized in the best possible way. According to the example shown in the drawing, the cntters have straight edges arranged parallel with the shaft 16. It should, however, be obvious that the cutting edges may run obliquely or screw-wise in relation to the shaft 16, provided only that they are so arranged that all cutting parts of the edges lie at the same radial distance from the geometric axis of the shaft 16, i. e. lie in the same cylindrical surface. By this arrangement of the edges an advantageous mode of cutting is also secured. It should be evident from the above that by the described devices the sharpened part of the pencil will not be given the shape of a cone with a rectilinear generator, but the shape of a cone whose generator forms part of an arc of a circle which during the rotation is described by the edges of the cutters, and that thus the exposed part of the lead approaches more closely to a cylindrical shape than the formed part of the wood, so that the lead will be given a shape particularly suitable for use, and very durable.

Having thus described my invention l declare that what I claim is:

1. A pencil sharpener comprising a supporting frame, a pencil holder associated therewith, a rotary shaft mounted in the frame, knife supporting arms projecting radially from said shaft, flexible knife blades carried by said arms so that the cutting edges are transversely disposed with respect to the axis of the pencil and rotate in a oylin drical plane about the aXis of said shaft, said arms having curved knife seats and means for detachably clamping the knife blades against said sea-ts whereby the blades are arched in cross-section.

2. A pencil Sharpener comprising a supporting frame, a pencil holder associated therewith, a rotary shaft mounted in the frame, knife supporting arms projecting `radially from said shaft, flexible knife blades carried by said arms so that the cutting edges are transversely disposed with respect to the axis of the pencil and rotate in a cylindrical plane about the axis of said shaft, said arms having curved knife seats, means for detachably clamping the knife blades against said seats whereby the blades are arched in crosssection and means for` reciprocating the knives in a direction axially of the shaft.

3. A pencil Sharpener comprising a supporting' frame, a pencil holder associated therewith,r a rotary shaft mounted in the frame, knife supporting,` arms projecting radially from said shaft, flexible knife blades carried by said arms so that the cutting edges are transversely disposed with respect to the axis of the pencil and rotate in a cylindrical plane about the axis of said shaft, said arms having curved knife seats, means for detachably clamping the knife blades against said seats whereby the blades are arched in cross-section and means whereby rotation of said shaft causes reciprocation of said arms axially of the shaft.

el. A pencil sharpener comprising a sup*- porting frame, a pencil holder associated therewith, a rotary shaft mounted in the frame` knife supporting' arms projecting radially from said shaft, iexible knife blades carried by said arms so that the cutting edges are transversely disposed with respect to the axis of the pencil and rotate in a cylindrical plane about the axis of said shaft, said arms having curved knife seats, means for detachably clampA ing the knife blades against said seats whereby the blades are arched in crosssection and vmeansv whereby rotation of said sha/fty causes reciprocationof said arms axially of the shaft, 4said means comprising two elements, one of which is a grooveand the other a device projecting therein and actuated thereby, one of said elements being' associated with the shaft and the other with said arms.`

A .pencil sharpener comprising,` a supporting' frame, a pencil holder associated therewith, a rotary shaft mounted in the frame, knife supportingl arms projecting radially from said shaft, flexible knife blades carried by said arms so that the cutting edges are transversely disposed with respect to the axis of the pencil and rotate in a cylindrical plane about the axis of said shaft, said arms having curved knife seats, means for detachably clamping` the knife blades against said seats whereby the blades are arched in cross-section and` means whereby rotation of said shaft causes reciprocation of said arms axially of the shaft., said means comprising' a groove in the shaft and ball associated with said arms, and a screw removably holding said ball in place and capable of adjusting the pressure on the ball.

In testimony whereof I affix my signature.

PER FRENELL. Vitnesses T. D. SCHAUMANN, A. X. KAizLssoN.' 

